Can someone with type 1 diabetes develop type 2 ?

No. Not unless the original diagnosis was incorrect. Type 1 diabetes is really autoimmune diabetes and requires insulin treatment, is ketosis prone, usually in thin people, etc. Many people mistakenly are called type 1 because they need insulin treatment but really have a form of very slow type 1 (sometimes called Late-onset Autoimmune Diabetes of Adulthood (LADA) or Type 1 1/2) — or have type 2 diabetes, treated with insulin and then, when they lose weight, eat properly and/or exercise more effectively, no longer need insulin as part of their treatment. So, if correctly diagnosed, the answer is no. if incorrectly diagnosed, then this is really a reclassification based either on new lab testing or treatment benefit (weight loss, for instance.)

SB